243 
Cone and Fertile Stem of Equisetum. 
whorl of the cone ; seven persist into the cone — three of the second, two of 
the third, one of the fifth, and one of the ninth orders. Above the last 
whorl of leaves fourteen meshes are initiated ; twelve of these are of the 
first order and are closed in the neighbourhood of the insertion of the 
annulus, and two of the third order extend into the cone. 
Turning to E . giganteum, twenty meshes originate and are closed in 
Cone A of this species : thirteen of the first, five of the second, and two of , 
Text-fig. 4. Longitudinal 
reconstruction of the xylem of Cone 
C of E. hyemale. Axial xylem 
black, traces and parenchyma white. 
Magnification circa 10. 
Text-fig. 5. Longitudinal recon" 
struction of the xylem of Cone A of E- 
giganteum. Axial xylem black, traces and 
parenchyma white. The circles, black on 
white and white on black, with a bar across 
them, represent strands passing from the 
annulus into the axis, but dying out before 
reaching the stele on the radii of the strands 
or meshes on which they are shown. Mag- 
nification circa 5. 
the third orders. Six more unclosed meshes originate in the upper part of 
the cone. No fresh meshes arise between the insertion of the annulus and 
the lowest whorl of sporangiophores in any of the cones of this species 
examined by me. But from analogy with other species, as well as from 
the fact that a certain number of meshes are constantly closed in the region 
of insertion of the annulus, the latter may presumably be regarded as 
a reduced whorl, and held to mark the position of a node when estimating 
the order of the meshes that originate above the last whorl of leaves (cf. also 
pp. 257-8). In Cone A there are eleven of these : two of the first order and 
